So I asked Terry yesterday if I need to update my jb4 in order to install my e85 harness... He suggested firmware update or ISO. But I am guessing he said both? Can you guys help me out here? I have the link for the ISO, just need some clarification.

If you are installing the flex fuel wires...just do the ISO mod while youre in there. It will take an extra 2 minutes. It makes the car feel so much better. But I guess to answer your question specifically, yes, you do need to at least update the firmware to the 8/17 update.

If you are installing the flex fuel wires...just do the ISO mod while youre in there. It will take an extra 2 minutes. It makes the car feel so much better. But I guess to answer your question specifically, yes, you do need to at least update the firmware to the 8/17 update.

I don't think the ISO mod is just an update. I believe there is cutting required. I'm going to check it out and do it myself.

Yeah, there is cutting required, you just have to cut a diode off the board, not hard at all. I told him because he was installing the flex fuel wires, that since he was already in there and had everything apart to go ahead and cut the diode to do the ISO mod.

Its very, very, very simple. Its easier to do that than it was to instal the E85 wires.

Yeah, there is cutting required, you just have to cut a diode off the board, not hard at all. I told him because he was installing the flex fuel wires, that since he was already in there and had everything apart to go ahead and cut the diode to do the ISO mod.

Its very, very, very simple. Its easier to do that than it was to instal the E85 wires.

I havent noticed any yet, and Ive had it installed for a few days now. Terry said there may be a transistor that needs to be upgraded later, but we will only find out later. So far though, no problems.

okay im a bit confused. i have the old g4 board, i have a n54 aswell not a n55. Im interested in doing this iso mod, update or w.e it is due to the positive feedback espiecally in this thread. How would I go about going from my old g4 board to the ISO mod or whatever it is everyone is talking about?

okay im a bit confused. i have the old g4 board, i have a n54 aswell not a n55. Im interested in doing this iso mod, update or w.e it is due to the positive feedback espiecally in this thread. How would I go about going from my old g4 board to the ISO mod or whatever it is everyone is talking about?

You dont. You dont have an N55...go to the N54 board and ask them. Apparently our JB4 board is already a G5 board and all we have to do in order to get ISO is cut a diode. Im pretty sure its much different on an N54 G4 board.

the process is the exact same its the cutting the diode and stuff like that im worried about.. all i have to do is order the 150$ upgrade and i get the new "black box" then i would have the g5 board but would have to do the same cut you do in order to get the ISO.. just wanted to make sure it was as easy as that and also how exactly how cut these diodes so nothing messes up

the process is the exact same its the cutting the diode and stuff like that im worried about.. all i have to do is order the 150$ upgrade and i get the new "black box" then i would have the g5 board but would have to do the same cut you do in order to get the ISO.. just wanted to make sure it was as easy as that and also how exactly how cut these diodes so nothing messes up

Maybe, Im not sure, really couldnt say as I dont have a N54. Either go to the N54 section here, or just go to Terrys site and read. Im sure you will find what your looking for, your just looking in the wrong section right now. But, it is just ordering the board and cutting the diode, then yes, its very simple to cut it.

Yeah, after you cut the diode, you install the ISO firmware. Also, my last sentence in my last post I meant to say "But, if it is.....", not but, it is. Im not sure if all it is is just ordering the board and cutting it, but if it is, its easy, lol.

Yeah, after you cut the diode, you install the ISO firmware. Also, my last sentence in my last post I meant to say "But, if it is.....", not but, it is. Im not sure if all it is is just ordering the board and cutting it, but if it is, its easy, lol.

So the iso is the latest firmware. after I cut my diode, I just did the Iso-C hex file. that's it. But my old firmware was back in July...or was I suppose to update something else too. lol

So the iso is the latest firmware. after I cut my diode, I just did the Iso-C hex file. that's it. But my old firmware was back in July...or was I suppose to update something else too. lol

Yes, ISO-c is the latest..for the ISO. If you dont cut the diode, then load the 8/17 firmware. If you cut the diode, load the ISO-C firmware. The only other thing would be to update the interface software to the newest version..12/23 I think..cant remember.